Guest Blog: Hermann Burchard on Siberian Hot Spot Tracks

Hello Dr. Burchard, You may remember we corresponded briefly a few years ago concerning my research efforts in Palo Duro Canyon Texas. However at the time I was working on the Traissic sediments rather than those of the Permian and knew little about radiometric ages of them or any influence massive basalt flows may have had on them. I am writting because I have recently formed my own company and significantly increased my income and so in the future may have funds to finance some work and the time to undertake it. Nothing definate and certainly nothing before late 2012 but I just read an article on flood basalts and thought of you and your research and thought I should drop a line to let you know I may renew my Palo Duro Canyon research and may extend it down into the Permian. Also in the coming months I will be working with others preparing materials for an AAPG field seminar to be held in Palo Duro Canyon in late August or early Sept of 2012 and any information you might have on the Permian sediments of this area might be appropriate for inclusion. Our concentration will be on petroleum exploration applications of the ideas we can illustrate with the rocks in the canyon but I intend to provide a solid background of academic data relevant to the canyon as well. Darryl Maddox (retired from Amarillo College) Wellsite Geological Services maddox7803@gmail.com 806-282-0328

Daryl, thanks for the msg (now dated, sorry). The point itself is mute as Chatterjee reports that the top of the Permian is nowhere exposed in Texas, more precisely there is not any spot where there is conformable contact between the Permian & Triassic. - Here is an abstract about the precise timing of the end-Permian events from a paper that just appeared in PNAS Early Edition. Burgess et al, abstract: The end-Permian mass extinction was the most severe loss of marine and terrestrial biota in the last 542 My. Understanding its cause and the controls onextinction/recovery dynamics depends on an accurate and precise age model. U-Pb zircon dates for five volcanic ash beds from the Global Stratotype Section and Point for the Permian-Triassic boundary at Meishan, China, define an age model for the extinction and allow exploration of the links between global environmental perturbation, carbon cycle disruption, mass extinction, and recovery at millennial timescales. The extinction occurred between 251.941 ± 0.037 and 251.880 ± 0.031 Mya, an interval of 60 ± 48 ka. Onset of a major reorganization of the carbon cycle immediately precedes the initiation of extinction and is punctuated by a sharp (3‰), short-lived negative spike in the isotopic composition of carbonate carbon. Carbon cycle volatility persists for ∼500 ka before a return to near preextinction values. Decamillenial to millennial level resolution of the mass extinction and its aftermath will permit a refined evaluation of the relative roles of rate-dependent processes contributing to the extinction, allowing insight into postextinction ecosystem expansion, and establish an accurate time point for evaluating the plausibility of trigger and kill mechanisms.